At the moment i experience several issues with multiple sonos devices on homey.
One device works ok. with 2 of more, the device selection is a mess (plays on other than intended device/ controls the other than intended device). I’ve got a confirmation from Athom this should be fixed in the sonos 4.0 app (the homey app that is). which i expect with homey 2.0 ish??
quesstion 3:
This can (at the moment) only be done by hardwiring the Homey jack output to a sonos input.
At point 3: for an alarm sound you can use the app Soundboard, for waking up you could use the sound of a rooster. Unfortunately this works onley via the Homey speaker or via the meantioned hardwire jack output.
Grouping is not yet possible with homey. For myself I found a solution for my problem. I have always grouped 4 sonos speakers, but when watching TV, sonos automatically ungroupes this(which I want). In the morning 1am I let Yonomi group the speakers, play 1 minute at 0% volume and then pauses. That way when I go for breakfast, sonos automatically starts playing my favorite radio with the 4 speakers grouped again.